The invention relates to a device for the metered filling of bulk material having a metering screw, which is arranged in a hollow cylinder shaped metering tube and which can be slid in a longitudinal axis (L) of the metering tube, having a closing head for closing a metering opening, wherein the closing head has a substantially conical surface.
The European patent publication EP 1 582 467 B1 discloses a metering device for the filling of bulk material, particularly into small bags, so-called stick pack packages. A bag is thereby formed from a film web, into which the tubular metering device projects.
Such devices comprise a vertically running metering tube having a metering screw, which can move in the axial direction and rotate therein. Bulk material which is to be filled in bags or other types of containers is poured from above into the metering tube and is discharged via the metering screw in metered portions into bags at the lower end of said metering tube. In order to interrupt the flow and portioning of the bulk material, the lower end of the metering tube can be closed with a sealing means.
A problem with this metering device is that when said metering device is open, the metered product is directed by the closing cone against the inside of the bag. In so doing, particles of the bulk material remain stuck to the inside wall of the bag. Particularly the quality and the impermeability of the cross-sealing seam, with which the bag is subsequently closed, can be compromised by these particles. In the case of conventional metering devices, it must therefore be ensured that when the part of the bag used to configure the cross-sealing seam passes the metering device, said metering device is already closed so that no contamination occurs. Because the metering time available as a rule limits the machine output or respectively the possible number of cycles, the possible machine output is lowered by this early closing of the metering device.
A metering device would be desirable, with which the bulk material to be metered is directed into the bag in such a way that it cannot stick to the bag's inside wall in the upper region of said bag during filling.